Post on 26-Dec-2015
Electron Configurations
You will need: 1. Your homework from Friday (Quantum Mechanical
Model in last week’s packet)2. Your homework from last night (Electron
Configuration Guided Reading in this week’s packet)
Anything that you see in white, you should write down
Bohr Model of Hydrogen
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 331
Nucleus
Possible electron orbits
e
e
Bohr Model of Hydrogen
• Bohr model = epic fail for all other elements
e
e
The Quantum Mechanical Model
The Quantum Mechanical Model• 2 parts of an atoms
–Nucleus –Electron cloud
»Where the probability of finding an electron is high
»Drawn as a fuzzy cloud»The cloud is more dense where the
probability of finding the electron is high.
More likely to find an electron
Less likely to find an electron
Nucleus
Electron cloud
The Quantum Mechanical Model• Atomic Orbitals
–Space around the nucleus –High probability of finding an
electron –Has a specific energy level–Has a specific sublevel
»Sublevels have different shapes
• Further describes where an electron is likely to be found
The Quantum Mechanical ModelAtomic orbital shapes: AKA: Angular momentum quantum number
S orbital Angular momentum quantum number (l) = 0
The Quantum Mechanical ModelAtomic orbital shapes:
P orbitals Angular momentum quantum number (l) = 1
The Quantum Mechanical ModelAtomic orbital shapes:
D orbitals Angular momentum quantum number (l) = 2
The Quantum Mechanical ModelAtomic orbital shapes:
F orbitals Angular momentum quantum number (l) = 3
Think-Pair-Share • Turn to your neighbor and…
–Explain what an orbital is–List the 4 shapes of atomic orbitals
Vocabulary• Quantum numbers: tell us the properties of
atomic orbitals and the properties of electrons in the orbitals
• Principle quantum number – Symbol: n – The energy level that an electron occupies
• Angular momentum quantum number– Symbol: l– The shape of the orbital
• Spin quantum number – +1/2 or -1/2 – Spin state of an electron
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2
3
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
3
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
4
Main energy level (n)
Sublevels(orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
p 3 6
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
p 3 6
d 5 10
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
p 3 6
d 5 10
f
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
p 3 6
d 5 10
f 7
Main energy level (n)
Sublevels (orbital shape)
Number of orbitals per sublevel
Number of electrons per sublevel
1 s 1 2
2 s 1 2
p 3 6
3 s 1 2
p 3 6
d 5 10
4 s 1 2
p 3 6
d 5 10
f 7 14
Electron Configurations
• Electron configuration:– The arrangement of electrons in an atom
• The lowest-energy arrangement of the electrons for each element is called the element’s ground-state electron configuration
Rules for writing electron configurations
• Aufbau principle: – An electron occupies the orbital of lowest-
energy first
1s 2s 2p3s 3p 3d4s 4p 4d 4f5s 5p 5d 5f6s 6p 6d 6f
Rules for writing electron configurations
• Hund’s rule: – Electrons occupy equal energy orbitals one
at the time – The electrons in each orbital have the
same spin – School bus rule
2px 2py 2pz
Rules for writing electron configurations
• Pauli exclusion principle: –Electrons in the same orbital must
have different spins
2px 2py 2pz
Think Pair Share
• Turn to your neighbor and explain the three rules for electron configurations in your own words
Orbital Diagram p. 105
Box = orbital
Arrow = electron
Up and down arrow = electrons with opposite spins
Electron Notations • Orbital notation
– Lines (or boxes) represent orbitals – Arrows represent electrons
He
Writing Electron Configurations 1. Locate the element on the periodic table
Writing Electron Configurations
2. Determine the number of electrons in the element
1. Locate the element on the periodic table
Writing Electron Configurations
3. Fill in the electrons in the orbital notation diagram starting at 1s (remember the rules)
2. Determine the number of electrons in the element
1. Locate the element on the periodic table
Writing Electron Configurations
4. Write the electron configuration from the completed orbital notation diagram
3. Fill in the electrons in the orbital notation diagram starting at 1s (remember the rules)
2. Determine the number of electrons in the element
1. Locate the element on the periodic table
Writing Electron Configurations
5. Calculate the number of electrons in the electron configuration and make sure it matches what you found in step 2
4. Write the electron configuration from the completed orbital notation diagram
3. Fill in the electrons in the orbital notation diagram starting at 1s (remember the rules)
2. Determine the number of electrons in an atom of the element
1. Locate the element on the periodic table
Orbital Notation
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =# of electrons = 3
Electron Notations • Electron configurations• Written in the following order:
1. Number of energy level2. Letter of sublevel 3. Number of electrons in each sublevel written as
a superscript 1s2Energy level
Sublevel
Number of electrons
1s22s22p6Energy levelsSublevels
Number of electrons
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1s
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1s2
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1s22
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1s22s
Electron Configurations
Aufbau principle: an electron occupies the orbital of lowest-energy first
Li =1s22s1
# of electrons = 3
Electron Configurations
C =
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
# of electrons = 6
Electron Configurations
C = 1
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s2
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22s
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22s2
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22s22
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22s22p
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
Electron Configurations
C = 1s22s22p2
Hund’s rule: electrons occupy equal energy orbitals one at the time with the same spin
# of electrons = 6
Electron Configurations
Ca = # of electrons = 20
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s2
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s2
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p6
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s2
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23p
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23p6
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23p64
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23p64s
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Ca = 1s22s22p63s23p64s2 # of electrons = 20
Pauli exclusion principle: electrons in the same orbital must have different spins
Electron Configurations
Cl = # of electrons = 17
Electron Configurations
Cl = 1
Electron Configurations
Cl = 1s
Electron Configurations
Cl = 1s2
Electron Configurations
Cl = 1s22
Electron Configurations
Cl = 1s22s
Electron Configurations
Cl = 1s22s2
Electron Configurations
Cl = 1s22s22
Electron Configurations
Cl = 1s22s22p
Electron Configurations
Cl = 1s22s22p6
Electron Configurations
Cl = 1s22s22p63
Electron Configurations
Cl = 1s22s22p63s
Electron Configurations
Cl = 1s22s22p63s2
Electron Configurations
Cl = 1s22s22p63s23
Electron Configurations
Cl = 1s22s22p63s23p
Electron Configurations
Cl = 1s22s22p63s23p5
Exit Ticket
• Fill out the worksheet that is being passed out
• Turn it in when you are finished • Begin working on tonight’s homework
– Save #4 for tomorrow night
sp
d (n-1)
f (n-2) 67
Blocks of the Periodic Table
1s
2s
3s
4s
5s
6s
7s
3d
4d
5d
6d
1s
2p
3p
4p
5p
6p
7p
4f
5f
1234567
Electron Notations • Noble gas notation
– The noble gas that comes before the desired element on the periodic table is written in brackets
– The rest of the electron configuration is written at the end • Energy level • Sublevel • Number of electrons
Sodium’s noble gas notation: [Ne]3s1Noble gas
Energy level Sublevel
Number of electrons
Electron Configurations
Fe = 1s
Electron Configurations
Fe = 1s2
Electron Configurations
Fe = 1s22
Electron Configurations
Fe = 1s22s
Electron Configurations
Fe = 1s22s2
Electron Configurations
Fe = 1s22s22
Electron Configurations
Fe = 1s22s22p
Electron Configurations
Fe = 1s22s22p6
Electron Configurations
Fe = 1s22s22p63
Electron Configurations
Fe = 1s22s22p63s
Electron Configurations
Fe = 1s22s22p63s2
Electron Configurations
Fe = 1s22s22p63s23
Electron Configurations
Fe = 1s22s22p63s23p
Electron Configurations
Fe = 1s22s22p63s23p6
Electron Configurations
Fe = 1s22s22p63s23p64
Electron Configurations
Fe = 1s22s22p63s23p64s
Electron Configurations
Fe = 1s22s22p63s23p64s2
Electron Configurations
Fe = 1s22s22p63s23p64s23
Electron Configurations
Fe = 1s22s22p63s23p64s23d
Electron Configurations
Fe = 1s22s22p63s23p64s23d6
Pauli exclusion principle: electrons in the same orbital must have different spins